Scissors or shears.



Patented Sept. 7, 1915.

E. HOLTGRAVE.

SCISSORS 0R SHEARS.

APPLICATION FILED Nov.2 1. 1914.-

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` SCIsSQRsORsHER-s Specification of Iietters'xlatent.' l Patented Sept.'7, 1915.

Applicatonfled N ov'ejmber 27, 1914; SeriallNo. 874,110.

To all whom t may concern .9 i g l' Be it known that I, ERNST HLTGRAVE,citizen of the United Statesof America, re-

siding at Brooklyn, in the county ofKingsA and State of New York, haveinvented certain new and useful Improvements in Scissors or Shears, ofwhich theV following is a specification.

The present invention relates to scissors or shears and particularly toan improvement on my former Letters PatentV No. 841,690, issued January22, 1907, and has for its object to provide means for easily slackeningand tightening the scissors or shears without the use of any tools.

My invention will be more fully understood by reference to theaccompanying drawing in which similar reference characters denotecorresponding parts and in which- Figure 1 is an elevation of myimproved shears, the head of the bolt being out off; Fig. 2 is a sectionon line 2 2 of Fig. 1; Fig. 3 is an enlarged perspective plan view ofthe middle part of the upper blade showing the cam groove and thenotches; Fig. 4 is a perspective bottom view of the member serving fortightening and slackening the scissors and Fig. 5 is a cross section online 5-5 of Fig. 4.

In my former patent, the device for tightening or slackening the shearsconsists of a spring member adapted to move on the slanting part of thesurface of the upper blade and according to the position of the springon said surface the blade is more or less pressed against the lowerblade. It has been found, however, that the device is not suiiicientlyeffective, particularly with large shears, first because the springwhich has to be made thin so as to permit its easy manipulation by thehand of the user does not exert enough pressure on the blade and yieldsduring the cutting action. Secondly, it aifects one of the blades only.The present invention obviates the above drawback.

a and b denote the two blades which at the point c are joined by aheaded screw-bolt d. The screw-bolt is passed through perforations a', bmade in the blades and is tightened as usually by` a nutV e. Between thehead d of the screw-bolt and the upper blade a a member f is insertedwhich is in form of a circular disk preferably of sheet metal formedwith a radial extension 7' which is bent to extend somewhat beyondthe'surface-of the bladen when in operative position and which is formedwith a downward'projection or nose f2. Arranged inthe :arc of a circlearound the center of the bolt and on the level part a of the surface ofthe upper blade are a number of notches a? into either of which the nosef2 of the member f is adapted to engage after proper adjustment thereof,so as to lock it in adjusted p0- sition. Projecting from the lowersurface of the member f is a wedge-shaped and circularly curvedprojection f3 which may be formed by stamping the disk-shaped part ofthe member f, as shown in Fig. 5. Formed in the part a of the upper orouter surface of the blade a is a groove a3 that surrounds the circularhole a and in shape corresponds to the projection f3.

The member f is so disposed relative to the blade a that normally, z'.e. when the shears are slackened, the highest part of the proj ection f3will engage the deepest part of the groove and as the member is turnedaround the bolt the projection f3 will gradually rise to the surface ofthe blade acting thereby as a Wedge between the head el of the screwboltand the blade a and consequently tighteningthe two blades veryeffectively. When the member is moved in opposite direction theprojection f3 will descend into the deeper part of the groove, relaxingthe pressure and slackening the blades. The adjustment of the degree oftightness or slackness between the blades is accomplished by hand byVsomewhat raising and subsequently turning the finger f of the member fin the desired direction and to the desired extent. On releasing thefinger after the proper adjustment has been obtained the nose f2 at theend of the linger will automatically engage the `corresponding notch a2in the blade a and will lock the member f in the adjusted position. Itwill be seen that because of the member acting as a wedge directlybetween the screw-bolt and the upper blade both blades will be equallyaffected.

While I have described one form of construction of my device, it isunderstood that the same may be easily modified without departing fromthe spirit of my invention and I, therefore, do not wish to limit myselfto the details described and shown.

WhatI claim and desire to secure by Letters Patent is:

Scissors or shears consisting oftwo blades, a headed bolt joining thesaid blades together, the blade opposite the head of the bolt having atthe forward end of its flat l0 formed in the outer face of the sai-dblade to Secure the member in adjusted position, Substantially as and.for the purpose set forth.

In testimony whereof I aix my signature in presence of two witnesses.

ERNST HOLTGBRAVE..

Witnesses Y E. BURNHAM, D. KLEIN.

Gopies 0f; this patent may' he obtained for vse cents each, byaddressingthe Commissioner of Patents,

Washjmgton,IlG.m

